Pushing Mach 1

In what is being termed the “Showdown at Blackrock” and “Duel in the Desert,” the land speed record is under assault on a desert plain in Nevada and could be bested several times in coming weeks as two supercars push the mark on the ground toward its last major barrier: the speed of sound. American Craig Breedlove’s “Spirit of America” and Britain’s Richard Noble’s Thrust SSC are tuning up in the Black Rock Desert of northwestern Nevada to challenge the record, which has stood at 633.468 miles per hour for nearly 14 years. The speed of sound (which changes with altitude and temperature) is about 750 mph in the mile-high Nevada desert.